Data Centre

ABSTRACT

The present disclosure relates to methods of enriching root powder products, for example beetroot powder. In particular, the methods relates to increasing the nitrate content and/or reducing the sugar content of the root powder product. The disclosure also relates to root powder products with increased with at least 3% nitrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/558,113, filed on Sep. 13, 2017, the contents of which ishereby incorporated entirely herein by reference.

BACKGROUND

Beetroot (also known as red beet or Beta vulgaris, but not to beconfused with sugar beet) products have been very popular the latestyears in part due to the surprising discovery that nitrate can reduceblood pressure, help maintain healthy blood pressure, improve athleticperformance, reduce oxygen consumption, and generally help with generalhealth, wellness and performance. Because beetroot is one of thevegetables containing the highest amount of nitrate (average range of1459 [644-1800] mg/kg fresh weight and as high as 4500 mg/kg of dryweight), beetroot has been the prime candidate for the development ofnatural nitrate containing products that also comply with regulationsestablished by the US Food and Drug Administration (FDA).

Advantages of using beetroot as a nitrate source include that it is anatural source and that beetroot can provide nitrate while complyingwith all standards and regulations established by the FDA and otherhealth organization unlike artificial sources of nitrate like sodiumnitrate. Another advantage is that beetroot can be available in“organic” form (according to the standards for “organic foods”established by the US Department of Agriculture (USDA) or other organicfood standards) for people who are interested in natural,pesticide-free, and additive-free nitrate sources.

Studies on the health benefits of nitrate increasingly emerged in thepast 10 years. According to the studies, the minimal dose of nitraterequired to produce effects is about 50 mg; however, the majority ofstudies show more significant results starting at 150 mg with therecommended amount being around 322 mg nitrate/day. It is notable thatmost of the studies regarding the benefits of nitrate supplementationhave been done on beetroot juice. Furthermore, and more importantly,beetroot juice high in nitrate supplementation has been shown to besuperior to supplementation with sodium nitrate containing equimolaramount of nitrate for athletic performance as well as for blood pressurereduction.

Despite the many potential benefits of red beet supplementation, it hasnot been practical for daily supplementation with beetroot products.First, not every person is willing to eat beets every day. Second, manyfind the “earthy” taste of beetroot, which is due to geosmin found inbeetroot, objectionable. Third, beets are naturally high in sugars,containing about 7 g sugars and a total of 10 g carbs per 100 g rawweight. More concentrated beet products, like beetroot juice or beetrootpowder have even higher amounts of sugars, containing 9-10 g sugars per100 ml. This can make consumption of beet products problematic forpeople who require low carbohydrate/sugar intake, such as diabetics orthose looking to lose weight. Finally, the high carbohydrate content perdry weight of beetroot or beetroot powder also makes it difficult tomake practical solid products, such as tablets, capsules or powder, thatcontain an efficacious dose of nitrate from beetroot juice.

All of the current beetroot dry products are either dried beetrootpowder product or dried beet juice products. The content of nitrate inexisting beetroot powder products is generally low, containing about 0.8to a maximum of 2.5% of nitrate by weight. Because of the low content ofnitrate in existing dried beetroot products, the vast majority does noteven state the exact amount of nitrates contained in the product. UsingVernier's nitrate ion-selection electrode, the amount of nitrate inthree popular powdered beetroot products marketed as “high in nitrate”actually only contained between 1% and 2.5% nitrate by weight.

Based on the concentration of nitrate in these “high in nitrate” driedbeetroot products, it is very impractical to add efficacious amounts ofbeetroot in dry supplements/food products. To achieve the minimumstudied dose of 157 mg nitrate, one would have to consume 15,700 mg or15.7 g of powder (if the powder contained 1% nitrate), which at minimumwould equal between 15 to 20 size 000 capsules. It is not surprisingthat no beetroot-based supplement to date can practically provide theefficacious dose of nitrate. Thus, the product labels falsely claim thebenefits of nitrate administration while containing non-efficaciousamounts. Accordingly, there is a long-felt need in the market forproducts made from beetroot higher in nitrate than 3%, which would allowfor convenient administration of efficacious doses of nitrate.

SUMMARY

The disclosure encompasses methods of increasing nitrate content andreducing sugar content in dried beetroot product. The methods comprisemixing dried beetroot product with an extraction mixture comprising analcohol and an acid, wherein the alcohol is a low molecular weightalcohol that is liquid at room temperature; steeping the mixture of thedried beetroot product and the extraction mixture to produce a steepedmixture; filtering the steeped mixture to produce a filtered product;and drying the filtered product to produce a dried filtered product. Insome implementations of the method, the alcohol is selected from thegroup consisting of: ethanol, methanol, propanol, isopropanol, andisobutanol. In some implementations of the methods, the acid is selectedfrom the group consisting of: acetic acid, formic acid, sulfuric acid,hydrochloric acid, nitric acid, hydrobromic acid, phosphoric acid, andperchloric acid. In one implementation, the ratio of the alcohol to acidin the extraction mixture is 3:1. In some embodiments, the extractionmixture is free of water. For example, the extraction mixture consistsof absolute ethanol and glacial acetic acid.

In some aspects, the mixture of the dried beetroot product and theextraction mixture is steeped for 24 hours prior to the filtering step.In some implementations, steeping the mixture of the dried beetrootproduct and the extraction mixture further comprising stirring themixture of the dried beetroot product and the extraction mixture.

In some implementations, the methods further comprise providing calciumhydroxide at a molar ratio of 2:1 to the acetic acid to the steepedmixture. In these implementations, the step of drying the filteredproduct does not exceed a temperature of 50° C. For example, drying thefiltered product comprises air drying or high vacuum drying the filteredproduct, or drying the filtered product comprises high vacuum drying thefiltered product at about 45° C.

The methods of increasing nitrate content and reducing sugar content indried beetroot product may further comprise rehydrating the driedfiltered product to produce a beetroot solution; adding an ethanolfermentation agent to the beetroot solution; fermenting the beetrootsolution containing the ethanol fermentation agent, wherein sugars inthe beetroot solution are converted into alcohol to produce fermentedliquid; removing the alcohol from the fermented liquid to produce anenriched product; and filtering the fermented liquid or enriched productto remove the ethanol fermentation agent. The fermentation agent isselected from the group consisting of: baker's yeast, brewer's yeast,and Zymomonas mobilis. In some implementations, the filtered liquid isfermented at about 40° C.

In some embodiments, the methods further comprise heating the fermentedliquid. In some aspects, removing alcohol from the fermented liquidcomprises drying the fermented liquid after the ethanol fermentationagent is filtered from the fermented beetroot juice. In other aspects,removing alcohol from the fermented liquid comprises spray drying of thefermented liquid after the ethanol fermentation agent is filtered fromthe fermented liquid. In some implementations, fermenting the beetrootsolution comprises stirring the beetroot solution containing thefermentation agent.

The disclosure also encompasses beetroot powder, wherein the beetrootpowder comprises at least 3% by weight nitrate, for example, more than4%, more than 5%, more than 6%, more than 7%, more than 8%, more than9%, or more than 10% by weight nitrate. In some embodiments, thebeetroot powder comprises less than 70% by weight sugar, for example,less than 65%, less than 60%, less than 55%, less than 50%, less than45%, less than 40%, less than 35%, less than less 30%, less than 35%,less than 20%, less than 19%, less than 18%, less than 17%, less than16%, or less than 15% by weight sugar. In some aspects, the beetrootpowder is produced according to the methods of the disclosure.

DETAILED DESCRIPTION

Detailed aspects and applications of the disclosure are described belowin the following drawings and detailed description of the technology.Unless specifically noted, it is intended that the words and phrases inthe specification and the claims be given their plain, ordinary, andaccustomed meaning to those of ordinary skill in the applicable arts.

In the following description, and for the purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the various aspects of the disclosure. It will beunderstood, however, by those skilled in the relevant arts, thatimplementations of the technology disclosed herein may be practicedwithout these specific details. It should be noted that there are manydifferent and alternative configurations, devices and technologies towhich the disclosed technologies may be applied. The full scope of thetechnology disclosed herein is not limited to the examples that aredescribed below.

The singular forms “a,” “an,” and “the” include plural referents unlessthe context clearly dictates otherwise. Thus, for example, reference to“a step” includes reference to one or more of such steps.

As used herein, the concentrations provided in percentages are byweight.

As used herein, the term “about” refers to a deviation of no more than+/−10% of the given value.

As used herein, the term “baker's yeast” refers to the yeast strain orcomposition of yeast strains commonly used as a leavening agent inbaking bread. Species of baker's yeast includes Saccharomyces cerevisiaeand Saccharomyces exiguus (also known as Saccharomyces minor).

As used herein, the term “brewer's yeast” refers to the strain of yeastor composition of yeast strains commonly used in brewing. These includestrains of S. cerevisiae and Saccharomyces pastorianus (formerly knownas Saccharomyces carlsbergensis). In some implementations, brewer'syeast comprises the Brettanomyces and/or Dekkera genii ofSaccharomycetaceae.

As referenced herein, the term “nitrate” refers only to the naturallyoccurring inorganic nitrate (NO₃ ⁻) present in vegetables, such asbeetroot. Accordingly, the amount or concentration of nitrate describedherein do not refer to any contribution of nitrate content from otherinorganic nitrate sources, such as potassium or sodium nitrate, that maybe added to the natural product.

Unless specified otherwise, the description of percentages in relationto a composition refers to a percentage by weight.

The present disclosure addresses the need to create a beetroot powderproduct that contain at least 3% (by weight) nitrate, which allows forconvenient daily administration of beetroot. The methods describedherein both enriches typical beetroot powder to have higher nitratecontent and reduces, if not removes, the sugar content in the beetrootpowder. For example, the methods described herein increase nitratecontent by at least three times, at least five times, at least tentimes, at least 15 times, or at least 20 times greater than theconventional beetroot powder. Another benefit of enriching the beetrootpowder according to the method of the present application is retainingthe activity of temperature sensitive nutrients, like antioxidants suchas betanin, as the process does not require heating above 50° C. In someaspects, the beetroot powder enriched according to the methods describedherein increases the antioxidant content by at least 10%, for example,about 10%, about 15%, about 20%, or about 25%, as compared to theconventional beetroot powder. Although the methods of the invention maybe practiced in conditions with a wide range of temperatures, roomtemperature is most preferable so that the antioxidants in the beetrootpowder are best protected during the process. While performing themethods of the invention at higher temperatures may damage theantioxidant content of the beetroot powder, performing the methods ofthe invention at higher temperatures will still yield a product withhigher nitrate and lower sugar content. The methods described herein mayalso be modified for similarly enriching the dried products of otherhigh nitrate vegetables, such as carrots and radishes.

The methods of the disclosure comprises combining the dried beetrootproduct, such as beetroot powder, with an extraction mixture comprisingan alcohol and an acid. In a preferred embodiment, the extractionmixture comprises alcohol and acid at a ratio of 3:1, or alternatively,75% by volume alcohol and 25% by volume acid. Although different ratiosof alcohol to acid will also produce products with higher nitrate andantioxidant content and lower sugar content than the original driedbeetroot product, the ratio of 3:1 produced the most optimal results.Any low molecular weight alcohol that is liquid in room temperature,such as ethanol, methanol, propanol, isopropanol, or isobutanol, may beused as the alcohol in the methods of the invention. The acid of theextraction mixture may be any acid, organic or inorganic, that is liquidat room temperature and can be easily removed by evaporation or vacuumdrying. For example, the acid in the extraction mixture may be aceticacid, formic acid, sulfuric acid, hydrochloric acid, nitric acid,hydrobromic acid, phosphoric acid, or perchloric acid. In a preferredembodiment, the extraction mixture comprises ethanol and acetic acid dueto their low price, easy availability and suitability for use in foodproducts. It is crucial for the optimal performance of the method thatall reactants are as free from water as possible. Existence of waterwill increase the sugar content of the product while decreasing thenitrate content. Accordingly, the extraction mixture, if comprisingethanol and acetic acid, preferably is made by mixing absolute ethanoland glacial acetic acid. In some implementations, the extraction mixtureconsists of the alcohol and the acid.

After combining the dried beetroot product with the extraction mixture,the mixture is allowed to steep, for example, for 24 hours. Thecombination of the beetroot product and the extraction fixture is thenfiltered to collect the liquid, which in some embodiments is a brightred liquid. The liquid that passes through the filter is then dried withan air draft, preferably at a temperature below 50° C. The filteredproduct may be further dried to further remove any moisture. Any dryingstep of the methods of the present application preferably happens at atemperature less than 50° C., which avoids loss of antioxidants.Accordingly, the drying step may be performed via air drying or dryingin a vacuum. For example, the filtered product may be dried under vacuumat about 49° C., about 48° C., about 47° C., about 46° C., about 45° C.,about 40° C., about 37° C., about 35° C., about 30° C., about 25° C.,about 22° C., about 20° C., about 17° C., or about 15° C. For drying ina higher vacuum (vacuum with pressure in the range from 100 mPa to 100nPa is a high vacuum), the drying temperature can be even lower, as theboiling temperature of water in high vacuum can be below 0° C. At thisstage, the dried filtered product lacks the characteristic earthy smelland taste of beetroot that can be tasted in the dried beetroot powder ofthe prior art. The dried filtered product also has increased nitratecontent compared to the starting dried beetroot powder. In someimplementations, the dried filtered product is ground into fine powder.

In preferred implementations, the combination of the dried beetrootproduct and the mixture of alcohol and acid is stirred during thesteeping stage. Sedimentation and congregation of the dried beet productat the bottom of the vessel containing the extraction mixture willhinder the extraction process. Accordingly, for example, the extractionmixture is stirred while the dried beet product is gradually added intoextraction mixture to avoid sedimentation and congregation of the driedbeet product at the bottom of the vessel containing the extractionmixture. In such embodiments of the methods, the stirred combination isallowed to settled prior to filtering to allow improved removal ofsolids. In some implementations, the methods further comprisecentrifuging the stirred extraction mixture to aid the removal of solidsand improve separation of solids.

Because acetic acid has a much higher boiling point than ethanol, themethods of implementation may further comprise adding calcium hydroxideprior to the drying step. The addition of calcium hydroxide results inthe formation of calcium acetate precipitate, which can be filtered outin the filtering step so that no acetate is found in the filteredliquid. The absence of acetate in the filtered liquid allows for dryingthe filtered liquid product at lower temperatures. In some aspects, theamount of calcium hydroxide added is a molar ratio of 2:1 calciumhydroxide to the amount of acetic acid in the extraction mixture. Insome implementations, the calcium hydroxide is added to the steepedcombination of the beetroot product and the extraction mixture prior tothe step of filtering the combination. Accordingly, the solids removedin the filtering step includes the calcium acetate precipitates as wellas solids from the beetroot product. In other implementations, thecalcium hydroxide is added to the liquid from filtering the steepedcombination of the beetroot product and the extraction mixture. Afterthe addition of calcium hydroxide, the solution is filtered again toremove any precipitates formed from the addition of calcium hydroxide.

The dried filtered product may be further enriched to possess higherpercentage of nitrate and reduced sugar level via ethanol fermentation.During ethanol fermentation, the sugars in the beetroot solution isconverted into alcohol to produce fermented liquid. Accordingly, in someembodiments, the methods further comprise rehydrating the dried filteredproduct, for example with water, to produce a beetroot solution;fermenting the beetroot solution containing the fermentation agent toproduce a fermented liquid; and removing alcohol from the fermentedliquid to produce an enriched liquid.

The ethanol fermentation agent may be baker's yeast, brewer's yeast, orZymomonas mobilis. In some implementations, the fermentation processcomprises stirring or mixing the beetroot solution and the fermentingagent. For example, the mixture is gently stirred at 100 rpm. In someaspects, the fermentation process can take place at a temperature of atleast room temperature, for example, at least 22° C., at least 25° C.,at least 30° C., at least 35° C., at least 40° C. In some aspects, thefermentation process takes place at a temperature no higher than 45° C.or no higher than 40° C. In certain implementations, the fermentationprocess takes place at a temperature of between about 22° C. and about30° C., for example, between about 22° C. and about 27° C., betweenabout 22° C. and about 25° C., or about 25° C.

In some implementations, the alcohol is removed by evaporating theliquids of the fermented liquid, for example, by drying the fermentedliquid. The preferred method of drying for commercial purposes is spraydrying. The end result is enriched beetroot powder. Prior to spraydrying, the ethanol fermentation agent is removed from the fermentedbeetroot juice, for example using a filter or by a centrifugation.

In other implementations, the alcohol is removed from the fermentedliquid by fractional freezing. As water freezes at a lower temperaturethan ethanol, the liquid ethanol may be separated from the frozen waterportion the fermented liquid (the enriched product). After fractionalfreezing to remove the ethanol, the enriched product can then be dried.In some implementations, the drying process includes evaporating theenriched product at about 60° C. or at less than about 50° C. In someimplementations, the evaporation process may take place in a vacuum. Inthese implementations, the ethanol fermentation agent is removed beforeor after fractional freezing but prior to drying the enriched product toproduce enriched and dried beetroot juice powder.

The present disclosure also encompasses beetroot powder that comprisesat least 3% by weight nitrate, for example, more than 4%, more than 5%,more than 6%, more than 7%, more than 8%, more than 9%, or more than 10%by weight nitrate. In some embodiments, the beetroot powder comprisesless than 70% by weight sugar, for example, less than 65%, less than60%, less than 55%, less than 50%, less than 45%, less than 40%, lessthan 35%, less than less 30%, less than 35%, less than 20%, less than19%, less than 18%, less than 17%, less than 16%, less than 15%, lessthan 10%, or less than 5% by weight sugar. In some aspects, the beetrootpowder is produced according to the methods described herein.

A person well versed in the art will understand that a variety ofproducts can be made from the dried filtered product or enriched productprepared from the dried beetroot product. For example, the powderproduced from drying the dried filtered product or enriched product maybe made into tablets and other orally discrete dosage forms, such ascapsules, cachets, pills, granules, pellets, beads, and particles. Insome implementations, the tablets and other orally discrete dosage formsexample, may optionally be coated with one or more enteric coatings,seal coatings, film coatings, barrier coatings, compress coatings, fastdisintegrating coatings, or enzyme degradable coatings. Multiplecoatings may be applied for desired performance.

Further, dosage forms may be designed for, by non-limiting example,immediate release, pulsatile release, controlled release, extendedrelease, delayed release, targeted release, synchronized release, ortargeted delayed release. For release/absorption control, carriers maybe made of various component types and levels or thicknesses of coats.Such diverse carriers may be blended in a dosage form to achieve adesired performance. In addition, the dosage form release profile may beeffected by a polymeric matrix composition, a coated matrix composition,a multi-particulate composition, a coated multi-particulate composition,an ion-exchange resin-based composition, an osmosis-based composition,or a biodegradable polymeric composition.

EXAMPLE 1

The nitrate content of commercial USDA organic beetroot powder wasanalyzed using a Vernier Nitrate electrode. The content of nitrate(expressed as nitrate ion) was 0.98% by weight. The commercial USDAorganic beetroot powder (50 g) was finely grounded using a mill and thengradually mixed with 500 ml of absolute ethanol/glacial acetic acidmixture. The absolute ethanol/glacial acetic acid mixture was made bymixing 375 ml of ethanol with 125 ml of glacial acetic acid. Thecomposition of dried beet powder and absolute ethanol/glacial aceticacid mixture was allowed to steep with 24 hours with stirring. After 24hours, the stirring was stopped, and the composition of dried beetpowder and absolute ethanol/glacial acetic acid mixture was allowed tosettle for 30 minutes prior to filtering. The filtered liquid productfrom the composition of dried beet powder and absolute ethanol/glacialacetic acid mixture was then air dried at 49° C. The resulting powderwas further dried under high vacuum at 45° C. to remove any waterresidues. The powder also lacked the characteristic earthy smell andtaste of beets from containing geosmin.

For analysis, one gram of the resulting product was dissolved in 100 mlof distilled water. The nitrate content assessed using the same Vernierprobe and found to be 5.5%. The refractometer detected a sugar contentof the dissolved powder (1 g powder in 10 ml water) was about 13%.

The remaining powder was reconstituted into liquid with 100 ml water.Two grams of brewer's yeast were added to the liquid, and the productwas covered and left to ferment at room temperature. After 24 hours, theyeast was filtered out, and the liquid dried first with an air draft andthen under high vacuum. The resulting bright red powder was againassessed with for sugar and nitrate content using the Vernier Nitrateelectrode. Sugar content was found to be 0% while nitrate content was7.5%.

EXAMPLE 2

A commercial manufacturer prepared enriched beetroot extract from beetpowder (produced from raw Beta vulgaris) according to the method ofExample 1 herein. The enriched beetroot extract produced by thecommercial manufacturer was analyzed for nitrate and sugar content andoxygen radical absorbance capacity (ORAC) value.

Using the Vernier Nitrate electrode, the nitrate content of the enrichedbeetroot content was 4.2% by weight.

According to the Certificate of Analysis from Eurofins Food Integrity &Innovation, the total amount of sugar in the enriched beetroot productis 55.3%, which is significantly less than sugar content of beetroot(between 80-90%). The sugar profile of the enriched beetroot extract is0.6% fructose, 0.6% glucose, 54.1% sucrose, less than 0.1% lactose, lessthan 0.1% maltose, and less than 0.1% galactose.

According to the Certificate of Analysis from Eurofins Food Integrity &Innovation, the ORAC value is 179 μmol TE/g. This is more than 10 timeshigher than the ORAC value of raw beets. According to the USDA databasefor the ORAC values of selected foods, the ORAC value for raw beet is1776 μmol TE/100 g, which is 17.76 μmol TE/g. In view of raw beetscontaining 87% water, the presumed ORAC value for beetroot powderproduced by evaporating water from raw beets would be about 137 μmolTE/g. Thus, the method described herein increases the antioxidantconcentration by about 25% in the enriched beetroot powder.

1-9. (canceled)
 10. A data centre including one or more controllable aircirculation systems, one or more aisles comprising a plurality of coldaisles interleaved between at least three hot aisles, a plurality ofrows of racks, each row being arranged parallel to at least one of theaisles, the data centre being so arranged that in use cooling airpasses, under the control of the one or more controllable aircirculation systems, from a cold aisle through the racks and/or throughthe racks to a hot aisle, and an access door providing access to atleast one of the aisles, the door being movable between an open positionallowing personnel access to the aisle and a closed position, whereineach cold aisle is defined between two adjacent rows of racks, each coldaisle has a width that is substantially constant along its length, thedoor has an aperture, the one or more controllable air circulationsystems comprises a controllable air intake arrangement accommodated inthe aperture of the door, the width of the door is wider than the widthof the aisle associated with the door, and the width of the aperture islarger than or substantially equal to the width of the aisle, the accessdoor is one of multiple such doors, each door providing access to arespective cold aisle, there is provided a cold air supply region fortransporting, under the control of the one or more air circulationsystems, cooling air, above the floor, via the respective doors to therespective cold aisles, the cold air supply region has a height greaterthan 1.5 m above the floor.
 11. A data centre according to claim 1,wherein the air intake arrangement is configured to be movable to anyone of at least five different positions, each position corresponding toa different level of openness.
 12. A data centre according to claim 1,wherein the controllable air intake arrangement comprises a row ofvertical blades arranged for rotation about a vertical axis, such thatthe air intake arrangement may be moved between closed and openpositions by means of rotation of the blades.
 13. A data centreaccording to claim 2, wherein the controllable air intake arrangementcomprises a row of vertical blades arranged for rotation about avertical axis, such that the air intake arrangement may be moved betweenclosed and open positions by means of rotation of the blades.
 14. A datacentre according to claim 3, wherein the blades extend across more than70% of the width of the door.
 15. A data centre according to claim 4,wherein the blades extend across more than 70% of the width of the door.16. A data centre according to claim 3, wherein a bar extendshorizontally across the door and supports one or more the blades, thebar being vertically positioned in the region between 20% and 80% of theheight of the aperture.
 17. A data centre according to claim 4, whereina bar extends horizontally across the door and supports one or more theblades, the bar being vertically positioned in the region between 20%and 80% of the height of the aperture.
 18. A data centre according toclaim 5, wherein a bar extends horizontally across the door and supportsone or more the blades, the bar being vertically positioned in theregion between 20% and 80% of the height of the aperture.
 19. A datacentre according to claim 6, wherein a bar extends horizontally acrossthe door and supports one or more the blades, the bar being verticallypositioned in the region between 20% and 80% of the height of theaperture.
 20. A data centre according to claim 3, wherein the bladesextend across more than 80% of the height of the door.
 21. A data centreaccording to claim 4, wherein the blades extend across more than 80% ofthe height of the door.
 22. A data centre according to claim 5, whereinthe blades extend across more than 80% of the height of the door.
 23. Adata centre according to claim 6, wherein the blades extend across morethan 80% of the height of the door.
 24. A data centre according to claim7, wherein the blades extend across more than 80% of the height of thedoor.
 25. A data centre according to claim 8, wherein the blades extendacross more than 80% of the height of the door.
 26. A data centreaccording to claim 9, wherein the blades extend across more than 80% ofthe height of the door.
 27. A data centre according to claim 10, whereinthe blades extend across more than 80% of the height of the door.
 28. Adata centre building suitable for forming a data centre according toclaim 1, wherein the data centre building includes one or morecontrollable air circulation systems, one or more aisles comprising aplurality of cold aisles interleaved between at least three hot aisles,a plurality of rows of rack storage areas, each row being arrangedparallel to at least one of the aisles, the data centre building beingso arranged that, in use, when racks of IT equipment are installed inthe data centre building to form a data centre, cooling air passes,under the control of the one or more controllable air circulationsystems, from a cold aisle through the racks and/or through the racks toa hot aisle, and an access door providing access to at least one of theaisles, the door being movable between an open position allowingpersonnel access to the aisle and a closed position, wherein each coldaisle is defined between two adjacent rows of rack storage areas, eachcold aisle has a width that is substantially constant along its length,the door has an aperture, the one or more controllable air circulationsystems comprises a controllable air intake arrangement accommodated inthe aperture of the door, the width of the door is wider than the widthof the aisle associated with the door, and the width of the aperture islarger than or substantially equal to the width of the aisle, the accessdoor is one of multiple such doors, each door providing access to arespective cold aisle, there is provided a cold air supply region fortransporting, under the control of the one or more air circulationsystems, cooling air, above the floor, via the respective doors to therespective cold aisles, the cold air supply region has a height greaterthan 1.5 m above the floor.
 29. A method of cooling electronic equipmentin a data centre according to claim 1, wherein the method comprises thesteps of: cooling items of electronic equipment by operating the one ormore air circulation devices to transport air above the floor to theracks in an aisle via the controllable air intake arrangementaccommodated in the aperture of a door associated with that aisle.
 30. Amethod of cooling electronic equipment according to claim 20, whereinair is transported above the floor to the door, via the controllable airintake arrangement accommodated in the aperture of the door, then into acold aisle.